longitude - Land Surveyors Dictionary - Land Surveyors United - Global Surveying Community2024-03-29T05:21:06Zhttps://landsurveyorsunited.com/almanac/feed/tag/longitudeCoordinate Reference Systemhttps://landsurveyorsunited.com/almanac/coordinate-reference-system2020-05-10T18:48:49.000Z2020-05-10T18:48:49.000ZJustin Farrowhttps://landsurveyorsunited.com/surveyors/justin<div><img src="https://storage.ning.com/topology/rest/1.0/file/get/4905211297?profile=RESIZE_400x&width=400"></div><div><p><span style="font-size:14pt;">A reference ellipsoid is the mathematical model of the shape of the Earth with the major axis along the equatorial radius. A geographic coordinate system uses longitude and latitude expressed in decimal degrees. For example, WGS 1984 and NAD 1983 are the most common datums today. Before 1983, NAD27 was the most common datum.</span></p>
<p> </p>
<p><span style="font-size:14pt;">Cartographers write spherical coordinates (latitudes and longitudes) in <a href="https://gisgeography.com/decimal-degrees-dd-minutes-seconds-dms/">degrees-minutes-seconds (DMS) and decimal degrees</a>. For degrees-minutes-seconds, minutes range from 0 to 60. For example, the geographic coordinate expressed in degrees-minutes-seconds for New York City is:</span></p>
<ul>
<li><span style="font-size:14pt;">Latitude: 40 degrees, 42 minutes, 51 seconds N</span></li>
<li><span style="font-size:14pt;">Longitude: 74 degrees, 0 minutes, 21 seconds W</span></li>
</ul>
<p><span style="font-size:14pt;">You can also express geographic coordinates in decimal degrees. It’s just another way to represent that same location in a different format. For example, here is New York City in decimal degrees:</span></p>
<ul>
<li><span style="font-size:14pt;">Latitude: 40.714</span></li>
<li><span style="font-size:14pt;">Longitude: -74.006</span></li>
</ul>
<h3><span style="font-size:14pt;">Latitude, Longitude and Spherical Coordinate System Grids</span></h3>
<p><span style="font-size:14pt;">When you put two coordinates together as a pair (X, Y), you can locate anything on Earth.</span></p>
<p><span style="font-size:14pt;">Latitude and longitude form our coordinate system grid.</span></p>
<p><span style="font-size:14pt;">Also, you can express coordinates in different ways. For example, you can use decimal degrees or degrees-minutes-seconds.</span></p></div>